Security forces opened fire Friday as thousands of anti-government protesters took to Syria's streets in a weekly ritual of defiance and demands for President Bashar Assad's ouster, activists said.
Syrian forces shot dead 15 protesters when they used live ammunition in several cities, activists and residents said.
Four were killed in Barzeh, a Damascus district 3 miles from the city center, said Syria-based human rights activist Mustafa Osso. He said they were felled by security forces' guns.
"The 'amn' (security police) first used teargas then they started shooting from rooftops when shoutings against Assad continued. Three youths were killed and I saw two bodies shot in the head and the chest," a resident of the main district of Barzeh — who gave his name as Hussam — said by phone.
"Barzeh has been surrounded by the army and police for days, but protests managed to break out from two mosques. The 'amn' are now chasing protesters in alleyways and firing randomly," he said, with the sound of bullets in the background.
But Syrian state television said gunmen, otherwise unidentified, had opened fire on security personnel and civilians, killing three civilians and wounding several security force members.
The Local Coordination Committees, a main activists' group, said it had the names of 14 civilians killed in the merchant city of Homs, the impoverished town of Kiswa south of Damascus and in Barzeh.
The Syrian Observatory for Human rights said one protester was also killed in the town of Qusair west of Homs on the border with Lebanon.
Protests in several other provinces also came under fire but it was not immediately clear whether there were casualties, said a spokesman for the group, Omar Idilbi.
'Bashar, you coward'
The committees said the deaths included a 12-year-old boy, Rateb al-Orabi, killed when security forces fired on protesters in the Shammas neighborhood in Homs, and a 13-year old boy in al-Kasweh. The reports could not be independently verified.
"Our revolution is strong! Assad has lost legitimacy!" protesters chanted in the Damascus suburb of Zabadani, according to video posted on YouTube. Another showed protesters chanting: "Oh Bashar, you coward, pack your bags and go to Iran."
The military crackdown has failed to silence a pro-democracy movement that has now lasted more than 100 days. The Syrian opposition says 1,400 people have been killed in the continuing government crackdown.
In northern Syria, activists said at least 15,000 people held a protest on the highway linking the country's two main cities, Damascus and Aleppo. Thousands marched in Amouda and Qamishli in the northeast and in other provinces, Osso said.
Dissidents reported a strong security presence in many locations. In Homs, all roads leading to the city center were reported blocked.
An eyewitness in Homs said protests took place in every city district Friday. He said hundreds of security personnel had been brought in by bus since early morning and encircled the city's center.
Witness: Grenades used
The witness said security forces fired smoke grenades in the Jouret al-Shiyeh district to disperse protesters.
He said pro-government thugs converged on Homs neighborhoods from neighboring villages and were "provoking" protesters, who began blocking roads with rocks to keep them back. He spoke on condition of anonymity for fear of reprisals.
In the central city of Hama, activists said a massive protest took place in the city's main Assi square. Online footage showed huge numbers of people gathered, many waving Syrian flags and crying for the regime's downfall. A large purple banner was unfurled over a building, reading: "Long live free Syria, down with Bashar Assad."
The video and other reports from inside Syria could not be independently verified, since the Damascus government has banned all but a few foreign journalists and restricted local media's reporting.
The Syrian regime blames foreign conspirators and thugs for the unrest, but the protesters deny any foreign influence in their movement, during which they say authorities also have detained 10,000 people.
The protests, which have occurred every Friday after weekly Muslim prayers, come as Syrian refugees stream across the border to safe havens in Turkey to escape a military sweep in Syria's northwest. More than 1,500 Syrian refugees crossed into neighboring Turkey on Thursday alone, boosting the number sheltered in Turkey to more than 11,700.
International condemnation on Damascus was mounting steadily. The European Union announced Thursday it was slapping new sanctions on the Syrian regime and U.S. Secretary of State Hillary Rodham Clinton said the movement of Syrian troops right up to the Turkish border could prove dangerous, as concerns of possible confrontations grew.
Citing residents on the ground, Osso said the military has deployed heavily in areas across the border from Turkey and set up checkpoints. He said the few thousand people who had been on the Syrian side of the border had all fled into Turkey.
"The few who did not were arrested," he said, adding 100 people were arrested in the past two days.
Tensions on Turkey border
Anticipating an exodus from Syria's second city, Aleppo, Turkish officials were setting up a sixth camp with up to 800 tents near a border crossing.
Turkish Foreign Minister Davutoglu told reporters Friday he had conveyed Turkey's "concerns and thoughts" about the operation near Turkey's border in a telephone conversation with his Syrian counterpart on Thursday.
He said he would continue to talk to Syrian officials to ensure that "reforms and peace are brought about as soon as possible."
"We hope that Syria is successful in renewing itself in a stable manner and comes out of the situation stronger. We will do all that we can to help," he said.
Earlier, Turkish troops moved back from positions near the border with Syria in an apparent attempt to prevent confrontations with Syrian troops, newspaper.
"Turkish troops moved their border positions several hundred meters back, apparently to avoid potential confrontations with Syrian units," Turkish Weekly said.
The newspaper said many of the refugees described fleeing the sound of gunfire and advancing tanks.
Witnesses said hundreds of terrified refugees crossed into Turkey to escape an army assault. Syrian troops stormed the village of Managh, 9 miles south of the border and just north of the commercial hub of Aleppo, according to residents.
"I was contacted by relatives from Managh. Armored personnel carriers are firing their machine guns randomly and people are fleeing the village in all directions," an Aleppo resident said.